GB/T 33811-2017 in English

Interpretation of GB/T 33811—2017 Technical Standard for Alloy Tool Steel Plate

1. Standard Overview

This standard specifies the ordering content, size, appearance, technical requirements, test methods and inspection rules for alloy tool steel plates. It is applicable to cold-rolled steel plates with a thickness not exceeding $4~\mathrm{mm}$ and hot-rolled steel plates with a thickness not exceeding $10~\mathrm{mm}$.

II. Comparison of standard frameworks

III. Technical requirements interpretation

1. Dimensions and appearance

Dimensional tolerance of cold-rolled steel plates:Comply with GB/T 708.

Dimensional tolerance of hot-rolled steel plates:For thickness $3~\mathrm{mm}$ and below, follow the provisions of Table 1; for thickness $3~\mathrm{mm}$, comply with GB/T 709-2006.

2. Chemical composition and smelting method

Grade and chemical composition:Table 3 lists the chemical composition range of each grade in detail, including the content requirements of chromium, molybdenum, tungsten, vanadium and other elements.

Smelting method:It is stipulated that the electric furnace $^+$ vacuum refining or electroslag remelting process shall be adopted. Special requirements shall be stated in the contract.

3. Technical parameters and quality control

Hardness requirements:Table 4 stipulates the upper limit of Brinell hardness of different grades in delivery state to ensure that the material has sufficient strength and wear resistance.

Non-metallic inclusions:Inspected according to GB/T10561-2005 A method, the qualified levels are divided into Group 1 and Group 2, and the default delivery is Group 2.

4. Surface quality and inspection rules

Surface quality:Cold-rolled steel plates are allowed to have slight pitting and scratches; hot-rolled steel plates are allowed to have iron scale, but the depth should not exceed the tolerance range.

Inspection items:Including chemical composition analysis, hardness test, macrostructure inspection, non-metallic inclusion assessment, etc., implemented according to Table 7.

IV. Implementation suggestions

1. Smelting and rolling control

• Strictly control the chemical composition deviation and add appropriate amount of alloy elements during the smelting process.
• Adopt electroslag remelting or vacuum refining process to ensure the purity of the material.

2. Inspection item optimization

• Select key inspection items according to actual use, such as hardenability, wear resistance, etc.
• Strengthen surface quality inspection to avoid early mold failure due to defects.

3. Customized solutions

• Specify special chemical composition or hardness requirements in the contract according to customer specific needs.
• Provide inspection reports and quality certificates to ensure that the materials meet national standards and contractual agreements.